1. Field of the Invention
The invention concerns a method of managing a network of databases to maintain the consistency of the data in the various data bases on the network.
2. Description of the Prior Art
A network of databases is used in an intelligent communication network. An intelligent communication network can easily offer new services to users thanks to a specific architecture comprising switching centers and dedicated machines. These dedicated machines control the services provided via the network. New services are introduced by modifying the software and the data of these dedicated machines. The network switching centers are not affected. This facilitates the introduction of new services.
The dedicated machines comprise:
a service management system (SMS) which is the center of the network in terms of data management; and PA1 service control points (SCP) which are the nodes at which the data is used to provide services. PA1 the provider of a service, who manages the data resulting from agreements entered into with the service subscribers; PA1 the subscribers to a service; for example, freephone subscribers can modify some service data such as the times at which calls are forwarded; PA1 the users of a service, who use the service data; for example, when users call a freephone number, the service data is used to translate the number called into a directory number. PA1 a relational database situated in the service management system and managed by a relational database management system (RDBMS); the data in this base is manipulated by the subscription management programs, under the control of the service provider, and by the subscriber access management programs, under the control of the subscribers; and PA1 databases accessible in real time, located in the respective service control points and each managed by a real time data management system RTDMS; these databases are accessible in real time for manipulation by programs which provide the services offered by the service control point, for example to translate a freephone number into a directory number. PA1 a table of the reference database is copied only into the database of a single service control point if the service to which it relates is provided at only one service control point; PA1 a table of the reference database is copied into the databases of several service control points if the service to which it relates is provided on a traffic sharing basis by a number of service control points, in which case the table is said to be "duplicated"; and PA1 a table of the reference database is partially copied into the databases of more than one service control point if the service to which it relates is provided on a resource sharing basis by these service control points, in which case the table is said to be "distributed". PA1 a relational database management system (RDBMS) located only in the service management system; and PA1 a real time data management system (RTDMS) located in the service management system and in each service control point. PA1 sending a data modification request in the SQL language from the application process to a pool of server processes of a relational database management system; PA1 assigning a server process to said request for the duration of its processing; PA1 sending the modification request in the dynamic SQL language from the server process pool to a relational database management system and executing said request; PA1 determining the databases accessible in real time to which the modification request relates; PA1 transferring said request to them in a form compatible with a management system of each database concerned; and PA1 executing the modification request in each database concerned.
Calls using the services of the intelligent network are routed to dedicated switching centers called service switching points which interrogate a service control point to provide the required services. For example, a service switching point can interrogate a service control point to obtain the translation of a freephone number (i.e., an "800" number) into a directory number.
The principal parties operating on the data managed by the intelligent telecommunication network are:
In one known type of intelligent network the services data is stored and managed in:
The relational database in the service management system is a reference database. The data constituting the databases of the service control points consist of data from the service management system database which is either duplicated in or distributed to the various service control points. There are three ways it can be divided between the databases:
Data management is provided by:
The two data management systems define data in the same way. The term "table" refers to data structures managed by these management systems. The RDBMS and the RTDMS can therefore share a common logical data model, although the systems have different physical organizations and different data manipulation languages. The RDBMS uses SQL (Structured Query Language) standardized by the American National Standards Institute. The RTDMS uses a set of real-time oriented primitives. From the data management point of view, an intelligent telecommunication network is therefore a heterogeneous network of databases. The complexity of implementation of application processes operating on the data depends on the characteristics of the database network manager. This implementation can be complex if the manager allows the application processes to see the heterogeneous nature of the network.
The distribution of data between a number of separate databases means that a database network manager (DBNM) is required which implements a data management process guaranteeing the consistency of data when application processes such as subscription management programs used by the service provider generate requests to modify data. The complexity of implementation of application processes operating on the data depends on the characteristics of the database network manager. This implementation can be complex if the manager allows the application processes to see the heterogeneous nature of the network.
A first object of the invention is to propose a management process which masks from application processes the multiplicity of data management systems and the differences between data manipulation languages, allowing application processes to modify the data in all the databases using a single type of request.